Google was just awarded U.S. Patent 9340178, for what is essentially a human flypaper coating for the hood of its autonomous vehicles. To the naked eye, the coating appears as ordinary car paint, but hides a multilayer, impact-activated adhesive, not unlike double-sided duct tape or flypaper. On colliding with a person, animal or other object, the adhesive instantaneously activates to hold the person to the hood. This prevents him from bouncing off the vehicle and into the street. The adhesive releases the person after a short period.
Curiously, the patent does not disclose the composition of the adhesive, calling it only “quick-acting” and “pressure-sensitive.” I would hope so!